allows scrolling backwards through history

frontend/src/datetime.ts

@@ -0,0 +1,49 @@
+// This function is slow
+export function getDateString(date: Date, utc: boolean, millis: boolean) {
+    const year = utc ? date.getUTCFullYear() : date.getFullYear();
+    const month = (
+        (utc ? date.getMonth() : date.getMonth()) + 1
+    ).toLocaleString('en-US', {
+        minimumIntegerDigits: 2,
+        useGrouping: false,
+        maximumFractionDigits: 0,
+    });
+    const day = (utc ? date.getUTCDate() : date.getDate()).toLocaleString(
+        'en-US',
+        {
+            minimumIntegerDigits: 2,
+            useGrouping: false,
+            maximumFractionDigits: 0,
+        },
+    );
+    const hour = (utc ? date.getUTCHours() : date.getHours()).toLocaleString(
+        'en-US',
+        {
+            minimumIntegerDigits: 2,
+            useGrouping: false,
+            maximumFractionDigits: 0,
+        },
+    );
+    const minute = (
+        utc ? date.getUTCMinutes() : date.getMinutes()
+    ).toLocaleString('en-US', {
+        minimumIntegerDigits: 2,
+        useGrouping: false,
+        maximumFractionDigits: 0,
+    });
+    const second = (
+        utc ? date.getUTCSeconds() : date.getSeconds()
+    ).toLocaleString('en-US', {
+        minimumIntegerDigits: 2,
+        useGrouping: false,
+        maximumFractionDigits: 0,
+    });
+    const milliseconds = (
+        utc ? date.getUTCMilliseconds() : date.getMilliseconds()
+    ).toLocaleString('en-US', {
+        minimumIntegerDigits: 3,
+        useGrouping: false,
+        maximumFractionDigits: 0,
+    });
+    return `${year}/${month}/${day} ${hour}:${minute}:${second}${millis ? `.${milliseconds}` : ''}${utc ? 'Z' : ''}`;
+}